teach Value::isDereferenceablePointer that byval arguments are always

dereferencable, noticed by inspection.

llvm-svn: 124085
This commit is contained in:
Chris Lattner 2011-01-23 21:15:29 +00:00
parent 1e7a9ee7d0
commit 9879965f4b
1 changed files with 4 additions and 0 deletions

View File

@ -363,6 +363,10 @@ bool Value::isDereferenceablePointer() const {
if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(this))
return !GV->hasExternalWeakLinkage();
// byval arguments are ok.
if (const Argument *A = dyn_cast<Argument>(this))
return A->hasByValAttr();
// For GEPs, determine if the indexing lands within the allocated object.
if (const GEPOperator *GEP = dyn_cast<GEPOperator>(this)) {
// Conservatively require that the base pointer be fully dereferenceable.